changelog: adds note about closing #12313

CHANGELOG.md

@@ -3,6 +3,10 @@
 * **Dataproxy**: Pass configured/auth headers to a Datasource [#10971](https://github.com/grafana/grafana/issues/10971), thx [@mrsiano](https://github.com/mrsiano)
 * **Cleanup**: Make temp file time to live configurable [#11607](https://github.com/grafana/grafana/issues/11607), thx [@xapon](https://github.com/xapon)
 
+### Minor 
+
+* **Api**: Delete nonexistent datasource should return 404 [#12313](https://github.com/grafana/grafana/issues/12313), thx [@AustinWinstanley](https://github.com/AustinWinstanley)
+
 # 5.2.0 (unreleased)
 
 # 5.2.0-beta3 (2018-06-21)